-LRB- CNN -RRB- -- Opening statements are set to begin Tuesday in the trial of self-help author and speaker James Arthur Ray , who is charged with three counts of reckless manslaughter in the death of three people at an Arizona sweat lodge .

The trial stems from a well-publicized incident that took place during a ceremony at a five-day retreat in Sedona , Arizona , on October 8 , 2009 . Two people died during the ceremony at Angel Valley Retreat Center . A third died nine days later , and -- authorities allege -- at least 15 others fell ill .

Ray could face up to 10 years in prison on each count if convicted . HIs attorney has argued that the author is not to blame for the deaths .

`` We do not seek to minimize the tragedy of the sweat lodge deaths , '' said a December 2009 letter to prosecutors from defense attorney Luis Li . `` But these deaths were not the result of criminal conduct . Mr. Ray and his team relied on Angel Valley to provide a safe environment , warned people of the risks , did not force people to participate , did not prevent them from leaving , and did everything they could to prepare for any problems and to assist when problems arose . ''

Prosecutors claim Ray , 53 , was reckless and that the lodge -- made of willow trees and branches , and covered with tarpaulins and blankets -- was heated to a perilously high temperature , causing the participants to suffer dehydration and heat stroke .

Ray also encouraged participants to hydrate throughout the retreat and warned them the sweat lodge would be very hot , his attorney has said . Participants signed a release form saying that the retreat activities could include a sweat lodge with enclosed spaces and high temperatures , Li said .

Kirby Brown , 38 , of Westtown , New York , and James Shore , 40 , of Milwaukee , died on October 8 . Lizbeth Marie Neuman , 49 , of Prior Lake , Minnesota , died on October 17 .

The sweat lodge ceremony consisted of eight rounds , with each round lasting 10 to 15 minutes . While they were not prevented from leaving , participants have said they were encouraged to wait until the breaks between rounds .

In interviews with authorities , some participants recounted feeling distress in the first few rounds . Later , they told police , people began to pass out , others began to vomit and still others went into shock . Some were encouraged to lie down in the dirt to seek relief from the heat .

'' -LRB- Ray -RRB- knew that people were in trouble , '' Tom McFeeley , Brown 's cousin , told HLN 's Jane Velez-Mitchell on Monday . `` Those calls for help were ignored . ''

Ray had conducted the Spiritual Warrior Retreat for six years at a cost of about $ 10,000 to participants . The sweat lodge , 5 feet tall and 23 feet wide , was built to accommodate up to 75 people . There was a pit in the center where heated rocks were placed . Ray poured water over them to create steam .

Prosecutors maintain that Ray psychologically pressured participants to remain in the lodge even when they were n't feeling well , contributing to their deaths .

Defense attorneys dispute that .

Li wrote in the 2009 letter that Ray `` did not lead or pressure participants into making a choice they otherwise would not have made . This was a five-day retreat , not a cult . The JRI -LRB- James Ray International , Ray 's company -RRB- philosophy is a practical approach to creating a successful life , not a religious practice . ''

-- Beth Karas is a correspondent for `` In Session , '' which airs weekdays 9 a.m. - 3 p.m. ET on CNN 's sister network , truTV .

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James Arthur Ray is charged with three counts of reckless manslaughter

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His attorney says the deaths were accidental

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Prosecutors say Ray heated the lodge to dangerous temperatures